1. Field of the Disclosure
This disclosure generally relates to an acceleration detection device and, more particularly, to an optical accelerometer for detecting the 3D acceleration.
2. Description of the Related Art
The accelerometer generally employs a spring connecting to a proof mass and calculates the amplitude and direction of an acceleration by detecting a position variation of the proof mass caused by the acceleration. The conventional accelerometers generally include the capacitive accelerometer and the optical accelerometer.
The conventional capacitive accelerometer includes a plurality of comb-like first electrode plates on a proof mass and a plurality of comb-like second electrode plates on a substrate, wherein each of the second electrode plates is inserted between two of the first electrode plates. Meanwhile, the proof mass is connected to the substrate through a spring. When an acceleration occurs, the capacitance between the first electrode plates and the second electrode plates changes and thus it is able to calculate the acceleration by monitoring a capacitance variation. However, problems of the capacitive accelerometer are that the capacitance variation is very small and difficult to be measured, and it is difficult to measure the acceleration more than two dimensions.
The conventional optical accelerometer includes a transmitting fiber on a proof mass and a detecting fiber on a substrate. The light emitted from a light source is optically coupled to the detecting fiber from the transmitting fiber. Meanwhile, the proof mass is connected to the substrate through a spring. When the vibration occurs, the light coupling between the transmitting fiber and the detecting fiber is changed and thus it is able to calculate the acceleration by monitoring a light coupling efficiency. However, the alignment between the transmitting fiber and the detecting fiber is not easy to implement.
Accordingly, the present disclosure further provides an optical accelerometer capable of detecting the 3D acceleration simultaneously.